System and method for measuring the thickness of material layers applied in the funnel of a cathode ray tube during manufacture

Abstract

A hand tool can be used for measuring the thickness of a carbon layer applied in a cathode ray tube funnel during manufacture of the tube. The hand tool includes a scribe with a cutting blade or point that extends under the control of the user relative to the rest of the tool. The extension of the scribe relative to the base of the tool, which may be a roller, rollers or a skid plate, indicates the thickness of the carbon layer. The tool can also be applied to measure the thickness of other material layers deposited on a substrate.

What is claimed is:  
     
         1 . A tool for measuring a depth or thickness of a layer of material applied on a substrate, said tool comprising: 
 a carriage    a scribe supported by said carriage; and    a control device for said scribe that extends said scribe relative to said tool;    wherein said by adjusting a position of said scribe using said control device, said depth or thickness of said layer of material is determined.    
     
     
         2 . The tool of  claim 1 , wherein said control device comprises an indicator for indicating a displacement of said scribe relative to said tool.  
     
     
         3 . The tool of  claim 1 , wherein said control device is a knob with a threaded passage therethrough that receives a threaded shaft on which said scribe is supported.  
     
     
         4 . The tool of  claim 1 , wherein said carriage is supported on at least one roller.  
     
     
         5 . The tool of  claim 1 , wherein said carriage further comprises a handle.  
     
     
         6 . The tool of  claim 1 , wherein said layer of material is a layer of carbon material and said substrate is an interior of a cathode ray tube funnel.  
     
     
         7 . A method of measuring a depth or thickness of a layer of material applied on a substrate with a tool comprising a scribe supported on a carriage, said method comprising adjusting a position of said scribe relative to said tool until displacement of said scribe indicates said depth or thickness of said layer of material.  
     
     
         8 . The method of  claim 7 , further comprising moving said tool over said layer of material, wherein said adjusting said position of said scribe comprises adjusting said position of said scribe until said scribe cuts through said layer of material to said underlying substrate when said tool is moved over said layer of material, said displacement of said scribe then indicating said depth or thickness of said layer of material.  
     
     
         9 . The method of  claim 8 , wherein said moving said tool over said layer of material further comprises rolling said tool over said layer of material on at least one roller supporting said carriage.  
     
     
         10 . The method of  claim 9 , wherein said displacement of said scribe is a vertical distance between an end of said scribe and said at least one roller.  
     
     
         11 . The method of  claim 7 , further comprising moving said tool over an exposed portion of said substrate adjacent to an edge of said layer of material, wherein said adjusting said position of said scribe comprises adjusting said position of said scribe until said scribe initially contacts said layer of material, said displacement of said scribe then indicating said depth or thickness of said layer of material.  
     
     
         12 . The method of  claim 11 , wherein said moving said tool over said exposed substrate further comprises rolling said tool over said exposed substrate on at least one roller supporting said carriage.  
     
     
         13 . The method of  claim 12 , wherein said displacement of said scribe is a vertical distance between an end of said scribe and said at least one roller.  
     
     
         14 . The method of  claim 7 , wherein said adjusting said position of said scribe comprises adjusting said position of said scribe until said scribe initially contacts said layer of material, said displacement of said scribe then indicating said depth or thickness of said layer of material; wherein a base of said tool rests on an exposed portion of said substrate and said displacement of said scribe is a vertical distance between an end of said extended scribe and said base.  
     
     
         15 . The method of  claim 7 , wherein said adjusting said position of said scribe is performed with a knob with a threaded passage that receives a threaded shaft on which said scribe is supported.  
     
     
         16 . The method of  claim 7 , further comprising reading an indicator that indicates said depth or thickness of said layer of material based on said displacement of said scribe relative to said tool.  
     
     
         17 . The method of  claim 7 , further comprising measuring a depth or thickness of a layer of carbon material applied on an interior of a cathode ray tube funnel.  
     
     
         18 . A device for measuring a depth or thickness of a layer of material applied on a substrate, said device comprising: 
 a scribe supported on a carriage; and    means for adjusting a position of said scribe supported on said carriage until displacement of said scribe indicates said depth or thickness of said layer of material.    
     
     
         19 . The device of  claim 18 , further comprising means for moving said tool over said layer of material, wherein said means for adjusting said position of said scribe is operated until said scribe cuts through said layer of material to said underlying substrate, said displacement of said scribe then indicating said depth or thickness of said layer of material.  
     
     
         20 . The device of  claim 19 , wherein said means for moving said tool over said layer of material further comprises at least one roller supporting said carriage.  
     
     
         21 . The device of  claim 20 , wherein said displacement of said scribe is a vertical distance between an end of said scribe and said at least one roller.  
     
     
         22 . The device of  claim 18 , further comprising means for moving said tool over an exposed portion of said substrate adjacent to an edge of said layer of material, wherein said means for adjusting said position of said scribe is operated until said scribe initially contacts said layer of material, said displacement of said scribe then indicating said depth or thickness of said layer of material.  
     
     
         23 . The device of  claim 22 , wherein said means for moving said tool over said layer of material further comprises at least one roller supporting said carriage.  
     
     
         24 . The device of  claim 23 , wherein said displacement of said scribe is a vertical distance between an end of said scribe and said at least one roller.  
     
     
         25 . The device of  claim 18 , wherein said means for adjusting said position of said scribe comprise a knob with a threaded passage that receives a threaded shaft on which said scribe is supported.  
     
     
         26 . The device of  claim 18 , further comprising means for indicating said depth or thickness of said layer of material based on said displacement of said scribe relative to said tool.  
     
     
         27 . The device of  claim 18 , wherein said device provides a means for measuring a depth or thickness of a layer of carbon material applied on an interior of a cathode ray tube funnel.